Adjustable linear friction device

ABSTRACT

An adjustable linear friction device for exercising the forearm, wrist and hand, comprising: a disc rotatably mounted on a housing, with a circumferential edge and opposed faces; a friction band extending between an anchor and biasing means, the friction band disposed against the circumferential edge of the disc; a shaft extending outwardly from the opposed faces, with handles on the shaft for rotating the shaft to effect rotation of the disc. Rotating the disc in a first direction results in a first normal friction between the friction band and the circumferential edge, and rotating the disc in a second and opposite direction results in a second, different normal friction. The device can be used to exercise the forearm and wrist joint in supination/pronation, extension/flexion, and radial/ulnar deviation motions through the full range of motion.

FIELD OF THE INVENTION

The present invention relates to exercise devices for working the forearm, wrist and hand muscles, and more particularly to such exercise devices employing frictional resistance.

BACKGROUND OF THE INVENTION

Various sports activities require a certain degree of arm/wrist strength and range of motion, particularly where an object is manipulated by the player's hands (e.g. a baseball bat). However, it is sometimes the case that a player does not possess the desired strength and range of motion. Participating in the particular sports activity while possessing inadequate strength or range of motion can sometimes result in an injury to the wrist muscles, which may entail a considerable recovery period if full recovery is even possible.

The wrist and associated muscles are involved in six primary forms of motion: forearm supination and pronation; wrist flexion and extension; and radiavulnar deviation:

-   -   Forearm supination/pronation: Supination is forearm movement         that causes the hand to be positioned palm-up, while pronation         is forearm movement that causes the hand to be positioned         palm-down. In supination/pronation, the axis of rotation passes         through the centres of both the radial and ulnar heads, and is         therefore not parallel to the longitudinal axis of the forearm,         pronation and supination resulting from rotation of the radius         about the ulna.     -   Wrist flexion/extension: Flexion is a downward/inward movement         at the wrist that results in the palm facing inward toward the         individual, while extension is an upward movement at the wrist         that results in the palm facing outward. The axis of rotation         passes through the centre of the capitate bone.     -   Radial/ulnar deviation: Deviation involves side-to-side movement         of the hand at the wrist. Radial deviation (also known as         abduction) is a rotation of the hand toward the thumb, while         ulnar deviation (also known as adduction) is a rotation away         from the thumb. The axis of rotation is a line perpendicular to         the plane of the palm through the intersection of the capitate         and lunate bones.

As inadequate strength or range of motion can result in serious injury, and the wrist is involved in a number of different forms of motion, it is therefore desirable to exercise the relevant muscles in such a way that the muscles are strengthened for all forms of motion and the range of motion for all forms of motion is improved.

There are many and diverse exercise devices known in the art, a number of which are specifically directed to wrist/forearm exercise, such as Canadian Patents Nos. 658,291 to Hotas and 1,134,404 to Brentham. However, despite their utility, such devices are generally directed to only a select type of wrist/forearm motion (e.g. only wrist flexion/extension), and accordingly provide limited benefits to the player who wishes to exercise the wrists and forearms through their entire range of motion for all primary types of wrist/forearm motion.

What is needed, therefore, is a device for exercising the forearm, wrist and hand, through their entire range of motion, for all primary types of wrist/forearm motion.

SUMMARY OF THE INVENTION

The present invention accordingly seeks to provide a frictional exercise device that can be used by a player to strengthen muscles of the forearm, wrist and hand, providing resistance for all six primary types of motion discussed above.

According to one aspect of the present invention there is provided a device for exercising forearm, wrist and hand, the device comprising: a housing; a discoid member having a circumferential edge and opposed faces, the discoid member rotatably mounted on the housing; an anchor member on the housing adjacent the circumferential edge of the discoid member; biasing means connected to the housing adjacent the circumferential edge of the discoid member and spaced from the anchor member; an elongate friction member extending between the anchor member and the biasing means, the elongate friction member disposed against the circumferential edge of the discoid member, the elongate friction member having a first end attached to the anchor member and a second end attached to the biasing means; a shaft extending outwardly from at least one of the opposed faces; and handle means on the shaft for rotating the shaft to effect rotation of the discoid member; such that actuation of the handle means effecting rotation of the discoid member in a first direction results in a first normal friction between the elongate friction member and the circumferential edge, and actuation of the handle means effecting rotation of the discoid member in a second and opposite direction results in a second normal friction between the elongate friction member and the circumferential edge.

In exemplary embodiments of the present invention, the device further comprises adjusting means on the housing connecting the biasing means to the housing, the adjusting means connected to the biasing means for selectively adjusting biasing effected by the biasing means, thereby selectively adjusting normal friction between the elongate friction member and the circumferential edge. Most preferably, the biasing means comprise first and second extension springs, and the adjusting means comprise: a threaded adjustment bolt mated with the housing; a nut threaded onto the threaded adjustment bolt, such that rotating the threaded adjustment bolt causes the nut to move axially along the threaded adjustment bolt; projections extending outwardly from the nut; a bar for connecting to the second end of the elongate friction member; and the first and second extension springs connected at respective first ends to the projections and at respective second ends to the bar; such that rotating the threaded adjustment bolt in a first direction causes the nut to move away from the discoid member, increasing the normal friction between the elongate friction member and the circumferential edge.

The biasing means are preferably an extension spring, while the anchor member is preferably a post extending from the housing at least partially past the circumferential edge of the discoid member. The elongate friction member is preferably a band composed of material sufficient to effect a desired coefficient of friction between the elongate friction member and the circumferential edge of the discoid member, and the elongate friction member is preferably in direct contact with the circumferential edge along greater than half of the extent of the circumferential edge.

The shaft preferably extends generally perpendicularly from the at least one of the opposed faces, and most preferably from each of the opposed faces. The handle means may be disposed either generally parallel to the opposed faces of the discoid member and generally perpendicular to the shaft, or generally perpendicular to the opposed faces of the discoid member and generally parallel to the shaft; this would be dictated by the type of motion the player wished to address in the exercise period, as described in greater detail below.

The device is also preferably provided with vertical support means, which most preferably comprise a base member and a generally vertical mast extending upwardly therefrom, the generally vertical mast connected to the housing.

A device according to the present invention, therefore, can provide the player with a resistance exercise means, where the resistance to applied torque is different depending on which direction the player rotates the shaft. Depending on how the handle means are positioned, as described in greater detail below, the player can also use a device according to the present invention to exercise the hand/wrist/forearm through all six primary types of motion, through the entire range of motion. In addition to improving a players ability, such exercise can help to prevent sports-related injury.

A detailed description of an exemplary embodiment of the present invention is given in the following. It is to be understood, however, that the invention is not to be construed as limited to this embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:

FIG. 1 is a detailed, simplified side elevation view of a housing, disc, and resistance means according to the present invention;

FIG. 2 is a partially cut away front elevation view of a device according to the present invention;

FIG. 3 is a partially cut away front elevation view of a device according to the present invention, with handles extending outwardly from the shaft perpendicular to the disc;

FIG. 4 is a partially cut away front elevation view of a device according to the present invention, with both handles parallel to the disc with free ends disposed in the same direction;

FIG. 5 a is a partially cut away front elevation view of a device according to the present invention, with both handles parallel to the disc but the free ends disposed in opposite directions;

FIG. 5 b is a partially cut away side elevation view of the device of FIG. 5 a; and

FIG. 6 is a detailed, simplified front elevation view illustrating tensioning means according to the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Referring now in detail to the accompanying drawings, there is illustrated an exemplary embodiment of a device according to the present invention generally referred to by the numeral 10. Referring specifically to FIG. 1, the device 10 comprises a housing 12, a disc 14 rotatably mounted in the housing 12, an anchor 24 mounted on the housing, and an extension spring 26 (connected to the housing 12 by means described in detail below). As can best be seen in FIG. 2, the disc 14 has first and second opposed faces 18, 20, and a circumferential edge 16. A friction band 48 is provided for creating friction when acting against the circumferential edge 16 of the disc 14, being connected to the anchor 24 at a first end 56 and connected at a second end 58 to the second end 30 of the extension spring 26 by means of a bar 66 (as described in detail below).

Referring now in detail to FIGS. 1 and 2, the device 10 further comprises a shaft 32, which connects to the disc 14 at the centre of the opposed faces 18, 20. In the exemplary embodiment, the shaft 32 passes through the disc 14 and housing 12, along the axis of rotation 22 of the disc 14, although it would be obvious to have two discrete shafts positioned one on each of the opposed faces 18, 20. As shown in FIG. 2, the shaft 32 is provided with handles 34, 36 to enable a user (not shown) to rotate the shaft 32 and thereby rotate the disc 14. The disc 14 may be rotated in a first direction of rotation 38 or a second direction of rotation 40, as described in detail below.

The device 10 further comprises adjusting means for adjusting the tension acting on the friction band 48. FIG. 6 illustrates the tensioning means in detail. In the exemplary embodiment, the adjusting means are in the form of a threaded adjustment bolt 42 mated with the housing 12, the connecting end 46 of the threaded adjustment bolt 42 receiving a nut 64, the nut 64 configured to move axially along the length of the threaded adjustment bolt 42 when the latter is rotated. The threaded adjustment bolt 42 is provided with a head 44 for rotation by the user. The nut 64 is provided with projections 68, which are connected to the first ends 28 of extension springs 26, 62. The second end 58 of the friction band 48 is connected to a bar 66, and the second ends 30 of the extension springs 26, 62 are also connected to the bar 66. When the head 44 is rotated in a first direction, therefore, the nut 64 is thereby withdrawn from proximity to the disc 14, pulling up on the extension springs 26, 62 and thereby increasing the tension on the friction band 48. When the head 44 is rotated in the opposite direction, the nut 64 is moved into closer proximity to the disc 14 and accordingly reduces the tension on the friction band 48.

The exemplary embodiment of the present invention also incorporates a support structure to assist in using the device 10. The support structure comprises a generally horizontal base 50, which serves as the support for a vertical mast 52. The mast 52 holds up the housing 12, and is connected to the housing 12 by means of a bracket 54. Preferably, the mast 52 is fully rotatable with respect to the base 50, which may take the form of a pin-and-socket arrangement (not shown).

The present invention seeks to provide frictional resistance as an aid to exercise. Friction is a resistive force that is a function of the force perpendicular to the contact surface (also called the “normal force”) and the coefficient of friction (which is a function of the materials brought into contact). In the exemplary embodiment of the present invention, friction is being generated between the circumferential edge 16 and the friction band 48 which is being forced against the circumferential edge 16.

As one end 56 of the friction band 48 is connected to a fixed anchor 24, rotation of the disc 14 in the first direction of rotation 38 will generate a first normal force. The other end 58 of the friction band 48 is connected to the extension springs 26, 62 (by means of the bar 66), so rotation of the disc 14 in the second direction of rotation 40 will generate a second normal force. As the anchor 24 is fixed, while the extension springs 26, 62 have an inherent flexibility, the first normal force will accordingly be greater than the second normal force, although using the threaded adjustment bolt 42 to increase the tension on the friction band 48 will narrow the difference between the first and second normal forces. The result is that a user may select either direction of rotation 38, 40 with the result that a different friction will be generated; if greater resistance is desired, for example, the user would select the first direction of rotation 38, but the second direction of rotation 40 would be selected if the user desired a lesser frictional resistance.

Referring now to FIGS. 3 to 5 b, various orientations of the device 10 are illustrated, specifically various handle positions/orientations, each addressed to a different set of the primary types of wrist/forearm motion set out above.

In FIG. 3, the handles 34, 36 are mounted on the shaft 32 such that the handles 34, 36 are parallel to the rotational axis 22 of the disc 14. The free ends 60 of the handles 34, 36, therefore, extend outwardly away from the disc 14. Various means for mounting the handles 34, 36 on the shaft 32 would be obvious to one skilled in the art. A user would employ this handle orientation to engage in exercises relating to wrist flexion and extension. For example, a user could rest their palms on top of the handles 34, 36 (left hand on the second handle 36, right hand on the first handle 34), then grasp the handles 34, 36 to establish a grip. The user could then either twist the handles 34, 36 in the first direction of rotation 38, resulting in wrist flexion through the full range of motion, or twist the handles 34, 36 in the second direction of rotation 40, resulting in wrist extension through the full range of motion. As stated above, the wrist flexion exercise in this case would be conducted at greater resistance than the wrist extension exercise; by turning the device 10 around by 180 degrees, the user could position the left hand on the first handle 34 and the right hand on the second handle 36, such that the wrist extension exercise would be conducted at a greater resistance than the wrist flexion exercise. The user could also choose to exercise with only one of the hands, the other hand either at rest or assisting in stabilizing the device 10.

Referring now to FIG. 4, a handle orientation is illustrated for use with radial/ulnar deviation exercises. In this orientation, the handles 34, 36 are disposed parallel to each other and to the disc 14, but perpendicular to the shaft 32. The free ends 60 of the handles 34, 36 point in the same direction. A user would engage in radial/ulnar deviation exercise using this orientation with both hands at the same time, as was the case with the wrist flexion/extension exercise orientation of FIG. 3 (although the user could also choose to exercise with only one of the hands, the other hand either at rest or assisting in stabilizing the device 10). The user would, for example, grasp the first handle 34 with the right hand and the second handle 36 with the left hand, palms facing toward the housing 12; moving the handles 34, 36 through the full range of motion so that the disc 14 moves in the first direction of rotation 38 would result in ulnar deviation, while movement through the full range of motion in the second direction of rotation 40 would result in radial deviation, the ulnar deviation being conducted at a greater frictional resistance as explained above. If the user wished to conduct the radial deviation exercise at the greater resistance, the device 10 would simply be rotated 180 degrees to allow the user's left hand to grasp the first handle 34 and the right hand to grasp the second handle 36.

Finally, FIGS. 5 a and 5 b illustrate a device 10 orientation for use with supination/pronation exercises. As can be seen in FIG. 5 a, the handles 34, 36 are disposed parallel to each other and to the disc 14, but perpendicular to the shaft 32, as was the case with the orientation illustrated in FIG. 4. However, unlike the orientation of FIG. 4, the free ends 60 of the handles 34, 36 point in opposite directions, and this orientation is intended to be used only one hand at a time. To use the device 10 with supination/pronation exercises, the user would be positioned at the side of the device 10 (i.e. facing a single handle as shown in FIG. 5 b). If a user were to grasp the handle 34 with their right hand, twisting the handle 34 through the full range of motion in the first direction of rotation 38 would result in supination at a greater resistance, while twisting the handle 34 through the full range of motion in the second direction of rotation 40 would result in pronation at a lesser resistance; switching to the left hand would result in pronation at a greater resistance and supination at a lesser resistance. If the user then simply rotated the device 10 by 180 degrees, grasping the second handle 36, the user could conduct supination of the right wrist/forearm at a lesser resistance, pronation of the right wrist/forearm at a greater resistance, pronation is of the left wrist/forearm at a lesser resistance, and supination of the left wrist/forearm at a greater resistance, opposite to what could be achieved when working with the first handle 34.

In addition, the exemplary embodiment allows for adjusting the resistance using the threaded adjustment bolt 42, so the various forms of exercise described above could be conducted at a variety of resistances as determined by the user to be desirable given the strength of the muscle group being worked. As the muscle group strength increased over time, the user could gradually adjust the resistance to enhance the benefits of the exercise.

While the exemplary embodiment illustrates different handles 34, 36 for use with the orientation set out in FIG. 3 as opposed to the orientations set out in FIGS. 4 to 5 b, it is also possible to have a uniform handle structure that could be employed with all orientations, capable of either parallel or perpendicular mounting on the shaft 32. Such a structure would be obvious to one skilled in the art.

While a particular embodiment of the present invention has been described in the foregoing, it is to be understood that other embodiments are possible within the scope of the invention and are intended to be included herein. It will be clear to any person skilled in the art that modifications of and adjustments to this invention, not shown, are possible without departing from the spirit of the invention as demonstrated through the exemplary embodiment. For example, various forms of support means could be employed with the present invention, including different mast 52 lengths for sitting or standing. Various friction band 48 and disc 14 materials could also be employed, as would be known to one skilled in the art, for generating different frictional resistances. Also, various means would be obvious for tensioning the friction band 48, for example using a compression spring for pressing the friction band 48 down onto the circumferential edge 16 (rather than extension springs 26, 62 for pulling the friction band 48 up against the circumferential edge 16), and various adjusting means would also be obvious to one skilled in the art. The invention is therefore to be considered limited solely by the scope of the appended claims. 

1. A device for exercising forearm, wrist and hand, the device comprising: a housing; a discoid member having a circumferential edge and opposed faces, the discoid member rotatably mounted on the housing; an anchor member on the housing adjacent the circumferential edge of the discoid member; biasing means connected to the housing adjacent the circumferential edge of the discoid member and spaced from the anchor member, an elongate friction member extending between the anchor member and the biasing means, the elongate friction member disposed against the circumferential edge of the discoid member, the elongate friction member having a first end attached to the anchor member and a second end attached to the biasing means; a shaft extending outwardly from at least one of the opposed faces; and handle means on the shaft for rotating the shaft to effect rotation of the discoid member; such that actuation of the handle means effecting rotation of the discoid member in a first direction results in a first normal friction between the elongate friction member and the circumferential edge, and actuation of the handle means effecting rotation of the discoid member in a second and opposite direction results in a second normal friction between the elongate friction member and the circumferential edge.
 2. The device of claim 1 further comprising adjusting means on the housing connecting the biasing means to the housing, the adjusting means connected to the biasing means for selectively adjusting biasing effected by the biasing means, thereby selectively adjusting normal friction between the elongate friction member and the circumferential edge.
 3. The device of claim 2 wherein the biasing means comprise first and second extension springs, and the adjusting means comprise: a threaded adjustment bolt mated with the housing; a nut threaded onto the threaded adjustment bolt, such that rotating the threaded, adjustment bolt causes the nut to move axially along the threaded adjustment bolt; projections extending outwardly from the nut; a bar for connecting to the second end of the elongate friction member; and the first and second extension springs connected at respective first ends to the projections and at respective second ends to the bar, such that rotating the threaded adjustment bolt in a first direction causes the nut to move away from the discoid member, increasing the normal friction between the elongate friction member and the circumferential edge.
 4. The device of claim 1 wherein the biasing means comprise an extension spring.
 5. The device of claim 1 wherein the anchor member is a post extending from the housing at least partially past the circumferential edge of the discoid member.
 6. The device of claim 1 wherein the elongate friction member is a band composed of material sufficient to effect a desired coefficient of friction between the elongate friction member and the circumferential edge of the discoid member.
 7. The device of claim 1 wherein the elongate friction member is in direct contact with the circumferential edge along greater than half of the extent of the circumferential edge.
 8. The device of claim 1 wherein the shaft extends generally perpendicularly from the at least one of the opposed faces.
 9. The device of claim 1 wherein the shaft extends outwardly from each of the opposed faces.
 10. The device of claim 1 wherein the handle means are disposed generally parallel to the opposed faces of the discoid member and generally perpendicular to the shaft.
 11. The device of claim 1 wherein the handle means are disposed generally perpendicular to the opposed faces of the discoid member and generally parallel to the shaft.
 12. The device of claim 1 further comprising vertical support means.
 13. The device of claim 12 wherein the vertical support means comprise a base member and a generally vertical mast extending upwardly therefrom, the generally vertical mast connected to the housing. 